The intensity of light measured in lux is

The intensity of light, measured in lux, is inversely proportional to the square of the distance between the light source and the object illuminated. A light hangs 6 ft above the center of a circular table 5 ft in diameter. If the illumination is 25 lux at the center of the table, what is it at the edge of the table? Round your answer to the nearest tenth.

The Charity Ball Committee sold $10 patron tickets, $5 sponsor tickets and $2. 50 donor tickets. The number of donor tickets sold was 24 more than the number of sponsor and patron tickets combined. There were 122 tickets sold, and the receipts totaled $562. 50. How many tickets of each type were sold?

A gold coin appreciated in value from $100 to $325 in 7 years. Find the average annual rate of aprreciation. Round to three significant figures.

A side of an equilateral triangle is 20 cm. The midpoints of its sides are joined to form an inscribed equilateral triangle, and this process is continued. Find the sum of the perimeters of the inscribed triangles if the process is continued without end

A vertical pole 15 m tall standing on a 20° slope is braced by two cables extending from the top of the pole to two points on the ground, 25 m up the slope and 25 m down the slop. How long are the cables? Round to three significant figures.

A cylindrical water tank 8 feet in diameter is lying on its side. What percent of its capacity is used when it contains water to a depth of 3 feet.